Toshiba TV29C90 problem; Image fades to black...

Don't adjust the H V adj..that's the high voltage adjustment!
You can get X-Ray leakage! Try to measure the ABL...
Automatic brightness limiter. If you have no voltage, you have
a ABL problem! If it's ok, try to slightly turn up the lower pot
on the flyback transformer..that's the screen conntrol. If you go
adjusting pots (and you shouldn't), mark them with a marker.
Clockwise is USUALLY increasing the adjustment! Turbo.
 
The first thing to do is clean & lube the
mode switch. Carefull of the mechanism
timing. Now, maybe the front buttons
aren't working. look for a "stuck" switch.
Turbo.
 
In article
<f0e36de8.0309071513.2e15eda4@posting.google.com>,
mark_bates@hotmail.com says...
I have a seemingly simple problem with my Panasonic SA-CH94M mini
system.

This machine has a 60-disc CD changer. The problem is, when I tell
the machine to play CD # 11, it plays the CD in slot number 12!

Educated guess only...
Click to expand...

The zero point is probably set by an optical sensor
(interrupter). It's possible the plastic tab that hits this
interrupter has accumulated enough dust that it's actually
interrupting a hair early.

IF this is the case, the interrupter is probably underneath.

--
Mark

The truth as I perceive it to be.
Your perception may be different.

Triple Z is spam control.
 
Thanks for the feedback. I don't know what ABL is...or where it is.
Any ideas? I don't know if there is a manual for this thing, but I
haven't got it anymore (maybe one that shows the schematic of the
monitor motherboard.) I am not a electronics guy, just someone trying
to get a monitor to work without having to squint at the dark screen.

How am I suppose to measure the voltage?

I am not sure what the flyback transformer is either. Is it labeled?

I have adjusted the setting on the monitor to their highest for
brightness and it is still too dark, so I opened it up and saw the SUB
BRIGHTENER and thought I could take a shot at that. I really want
this monitor too work because I have a load of work to do, but very
little cash to upgrade right now.

Thanks for you help!


On Sun, 7 Sep 2003 22:23:08 -0230, "Turbo" <Turbo@roadrunner.nf.net>
wrote:

Don't adjust the H V adj..that's the high voltage adjustment!
You can get X-Ray leakage! Try to measure the ABL...
Automatic brightness limiter. If you have no voltage, you have
a ABL problem! If it's ok, try to slightly turn up the lower pot
on the flyback transformer..that's the screen conntrol. If you go
adjusting pots (and you shouldn't), mark them with a marker.
Clockwise is USUALLY increasing the adjustment! Turbo.
Click to expand...
 
The usage current ( Amp )of your Electronic appliance is also very important
for selecting your step down transformer.

Cyrus
"Adrian" <adi007@germanynet.de> wrote in message
news:3f5bcd19$0$2334$9b4e6d93@newsread2.arcor-online.net...
Hello,

I've imported an electronic aplliance from Japan
which comes with a charge-adapter. The adapter is
designed for Japanese power (100V/60Hz) and sockets.

I live in Europe and have 230V/50Hz. The charge-adapter
takes 100V @ 60 or 50 Hz. All AC-AC-transformers I've
seen so far here output 110V @ 60 Hz. Am I right
that I can use such transformers for my Japanese equipment ?

The descriptions of the transformers say all "for US appliances",
but in the US you have 120V/60Hz, don't you ? So the
transformers should be suitable for both US and Japanese
appliances to work with as the 110V are in
tolerance for both 100 and 120V ? (But don't probably
can use Japanese appliances with US power, do you ?).

Are Japanese and US wallsocket mechanically identical ?

Thanks,
Adrian
Click to expand...
 
Apex is meant to be throw away. If you want to repair one, check out the
http://www.nerd-out.com forums. Pretty simple mechanical things go wrong
with them. However at 50 bucks a pop, what's your time worth? :)

Arthur Jernberg wrote:

Our directive on the APEX units is to rethurn them to the vendor if under
warrenty or service contract besause they do not support their products
with
service parts, diagrams, or technicial information: neither the teles or
dvd
players.
"dave" <k8sjs@sbcglobal.net> wrote in message
news:JeR4b.17860$Ih1.6763231@newssrv26.news.prodigy.com...
I had read that apex did'nt plan on repair or replacement parts
for this unit...a buy and replace deal....I have one too but
not
used much.....still ok...but I will throw it away if anything
happens.....
Click to expand...
--
Mark Wolfe http://www.wolfenet.org
gpg fingerprint = 42B6 EFEB 5414 AA18 01B7 64AC EF46 F7E6 82F6 8C71
Facts do not cease to exist because they are ignored.
-- Aldous Huxley
 
Try turning up the sub brightness control, that's about the only thing
you're gonna be able to do without reasonably extensive knowledge of
monitors and electronics in general. The manual was probably a few pages
outlining the basics of operating it, schematics haven't been readily
available for consumer electronics since the late 70's, these days they
usually cost more to get than the item is worth.


"david" <johnsonholding@yahoo.com> wrote in message
news:3t0olvokf2k561rk866feg333mua5ibcfl@4ax.com...
Thanks for the feedback. I don't know what ABL is...or where it is.
Any ideas? I don't know if there is a manual for this thing, but I
haven't got it anymore (maybe one that shows the schematic of the
monitor motherboard.) I am not a electronics guy, just someone trying
to get a monitor to work without having to squint at the dark screen.

How am I suppose to measure the voltage?

I am not sure what the flyback transformer is either. Is it labeled?

I have adjusted the setting on the monitor to their highest for
brightness and it is still too dark, so I opened it up and saw the SUB
BRIGHTENER and thought I could take a shot at that. I really want
this monitor too work because I have a load of work to do, but very
little cash to upgrade right now.

Thanks for you help!


On Sun, 7 Sep 2003 22:23:08 -0230, "Turbo" <Turbo@roadrunner.nf.net
wrote:

Don't adjust the H V adj..that's the high voltage adjustment!
You can get X-Ray leakage! Try to measure the ABL...
Automatic brightness limiter. If you have no voltage, you have
a ABL problem! If it's ok, try to slightly turn up the lower pot
on the flyback transformer..that's the screen conntrol. If you go
adjusting pots (and you shouldn't), mark them with a marker.
Clockwise is USUALLY increasing the adjustment! Turbo.
Click to expand...
 
On Mon, 08 Sep 2003 15:25:41 +0200, Adrian <adi007@germanynet.de>
wrote:

Hello fidik,

Transformers do not change the frequency, just effective voltage.


I know that, if you read my message you'll find that I say
that the transformer outputs 110V@50Hz not 60Hz. That's
not what I asked but whether the 110V of the transformer
would be in tolerance for my 100V charge adapter.

greetings,
Adrian
Click to expand...
If it is 110V. It may be highter. The socket will be the same though.
 
I should have been more specific when I last responded to your questions.
Actually, measuring the DC level with a voltmeter isn't going to be really
accurate, since the sync levels will be obscured by the average-responding
voltmeter. You really need to look at the video there with a DC coupled
scope. Measure the tips and the porches of the sync pulses with the scope.
Then, we'll know what kind of gain and DC levels we'll need.
Cheers!!
--
Tweetldee
Tweetldee at att dot net (Just subsitute the appropriate characters in the
address)

Time is what keeps everything from happening all at once.
"Louie" <beavisnbutthead@softhome.net> wrote in message
news:2kS6b.288057$Oz4.77652@rwcrnsc54...
yeah, i can put together a circuit OK and wire it up, but damn! i been
delayed a couple of days. i tried what you suggested, but then the 12V
power supply went out and when i got a new one i discovered that the
power socket on this unit is not standard. so i had to unsolder the
power socket and can't get a new one till tomorow.
then i'll be able to proceed.
Louie

Tweetldee wrote:


Before we go off to design a level shifter, why don't you measure the DC
voltage at pin 5, so we can see if it even needs to be done. If it
becomes
necessary, then a simple non-inverting op-amp stage with a DC offset
trimmer
could be the ticket. But, first things first.
How good are you in circuit construction? Since we're talking about
handling video here, circuit layout, construction and shielding are
important. That answers your last question... yes, shielding is quite
important.
Click to expand...
 
On Sun, 07 Sep 2003 15:12:52 -0400, david <johnsonholding@yahoo.com>
wrote:

Ok, I had read some old posts on the subject and here goes:

I have an older Daytek DT-1731D monitor. The brightness is really low
but useable with much harm to my feeble eyes ;)
Click to expand...
Does it have a Samsung CRT with a blue and white label? If so, that is
likely your problem.

Tom

So, I opened up the monitor with the usual precautions. I found a few
white nobs with Phillips heads on them : They are in two locations :

1st location : (left)
Sub-BGT ( I am guessing this is the SUB BRIGHTNESS)
HV ADJ

2nd Location (back)
G-Gain
R-Gain
Sub-Con (guessing the Sub CONTRAST)

Now, my big question is :

1) which way do the knobs turn for UP BRIGHTNESS (clock or counter)?
2) Which should I adjust to get a brighter picture (SUB BRIGHT or SUB
CONTRAST)?
3) Can I test these while the computer is running to see the affect?

Thanks in advance.

DAvid
Click to expand...
 
We need Model Number and Chassis number
as RCA has made hundreds of different Models.


kip

--
"Watch the return E-Mail addy its false"
"Marsha" <nospamplease@nosuchplace.com> wrote in message
news:aW67b.950$5M.24032@dfw-read.news.verio.net...
Our RCA Big Screen Projection TV messed up right when the warranty ended!
The picture looks curved now, you can still watch it. At first the good
screen would try to come in & the curved screen would try to come in, &
one
morning while watching we heard a lot of noise & now it is just the curved
screen. Anyone know what went out & about how much to fix?
Thanks,
Marsha
Click to expand...
 
www.mouser.com
no minimum

I like www.newark too if you have a $20 order.
I know how you feel - it's really irritating when you need a .50 part and
you end up paying $6 to ship it.


"Tom" <no-spam-for-me@home!.comm> wrote in message
news:Xx97b.270$mk1.8591@eagle.america.net...
Capacitor....$0.30. Handling charge per capacitor..... $2.00. Minimum
order... priceless. $25.00.
NTE1797 IC chip..... no stock.

Sheeeeesh!

Where do you shop
--
All outgoing mail scanned with Norton AntiVirus 2003
Click to expand...
 
"Tom MacIntyre" bravely wrote to "All" (08 Sep 03 22:11:08)
--- on the heady topic of "Re: Turning up Monitor Brightness - from the
sub-brightness ?"

TM> From: Tom MacIntyre <tom__macintyre@hotmail.com>

TM> Does it have a Samsung CRT with a blue and white label? If so, that is
TM> likely your problem.

I have a similar Orion crt in a flaky monitor. I don't know what's wrong
with it. I set the white level then bias and drive according to the
light calibration and it should be okay but the yellow bar looks yech,
almost beige like. Can't figure out what is wrong...

Asimov
******

.... I know flyback, ultor, and 47 other dangerous words.
 
Suspect the convergence power supplies or the PCC circuits.
"Marsha" <nospamplease@nosuchplace.com> wrote in message
news:aW67b.950$5M.24032@dfw-read.news.verio.net...
Our RCA Big Screen Projection TV messed up right when the warranty ended!
The picture looks curved now, you can still watch it. At first the good
screen would try to come in & the curved screen would try to come in, &
one
morning while watching we heard a lot of noise & now it is just the curved
screen. Anyone know what went out & about how much to fix?
Thanks,
Marsha
Click to expand...
 
Highly suspect actually is the crt.
"Randy J. Evans" <rjevans@powersupply.net> wrote in message
news:caf78900.0309060852.7bf80384@posting.google.com...
Zenith Color TV
R-Line
Model # SR2568S
Chassis # C10

The Purity is excellent, the Convergence is off only slightly, and
shouldn't
be noticeable to an untrained eye. The problem is the lower half of the
picture has a green cast to it at times, especially when the camera goes
from a fairly close up shot, to a camera shot that is pulled back, for a
panoramic type view. If a camera shot has someone centered on the screen,
from their neck down it has a green cast, the fleshtones from their neck
up
are not too bad, and near the top of the screen it will also take on a
greenish cast.
This set uses an LA7672 Jungle IC, and the Picture Tube is # A63AGD01X
At times the picture looks perfect, although every few seconds, you can
actually see the Tint change, like some type of Correction Circuit kicking
in. I've seen this on a few other Zeniths, and it's a very annoying
phenomena.
So, using an NTSC Pattern Generator, Purity, and Convergence looks A-OK,
but
when actually receiving a broadcast signal, the problems present
themselves.
The B&W Tracking is good, as is Vertical Size, and Horizontal Width.
I know my that my explanation of the problem is sketchy at best.

Any Ideas appreciated ??

Thanks,
Randy J. Evans
Click to expand...
 
I suspect that at least one of the convergence amp is bad. This is a
fairly common failure; often from poor solder connections of bad
capacitors as the original cause.

This is probably a task for a good repair shop. The convergence
generally has to be realigned (adjusted) after one or more amps are
replaced. A general cost would be about $250 - $350. If it is done
correctly, there is quite a bit of labor involved. I generally spend
about a hour or so doing adjustments and checking things after the
problem(s) is corrected, Some shops are hasty and attempt to get it in
& out ???; in which case you can expect "colored borders" around objects
at various locations on the screen.


Marsha wrote:
Our RCA Big Screen Projection TV messed up right when the warranty ended!
The picture looks curved now, you can still watch it. At first the good
screen would try to come in & the curved screen would try to come in, & one
morning while watching we heard a lot of noise & now it is just the curved
screen. Anyone know what went out & about how much to fix?
Thanks,
Marsha
Click to expand...
 
I should have addressed a possible pincushion problem. You did not
mention were the curves were. If the picture is hour-glass shaped
(sides are bowed in) but the colors seemed ok; then you are talking
about a pincushion problem. In which case the cost of repair is
probably less.

If one or more of the colors are apparently misaligned with each other
then the problem is in the convergence amps or their power supply. In
this case, the bowing could be either or both in the horizontal or
vertical. The key is that the colors would be obviously messed up.

Marsha wrote:

Our RCA Big Screen Projection TV messed up right when the warranty ended!
The picture looks curved now, you can still watch it. At first the good
screen would try to come in & the curved screen would try to come in, & one
morning while watching we heard a lot of noise & now it is just the curved
screen. Anyone know what went out & about how much to fix?
Thanks,
Marsha
Click to expand...
 
Can your test gen put out a mid grey type of raster for testing? I have
a feeling that the mask in the CRT is defective, or the purity
adjustment is out. If it cannot be adjusted out with the purity setup,
it has to be the tube, from what I have experienced.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
==============================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
Instruments http://www.zoom-one.com/glgtech.htm
==============================================
"Arthur Jernberg" <stubby@comcast.net> wrote in message
news:SdqcnXhVBYAzO8CiXTWJkw@comcast.com...
Highly suspect actually is the crt.
"Randy J. Evans" <rjevans@powersupply.net> wrote in message
news:caf78900.0309060852.7bf80384@posting.google.com...
Zenith Color TV
R-Line
Model # SR2568S
Chassis # C10

The Purity is excellent, the Convergence is off only slightly, and
shouldn't
be noticeable to an untrained eye. The problem is the lower half of
the
picture has a green cast to it at times, especially when the camera
goes
from a fairly close up shot, to a camera shot that is pulled back, for
a
panoramic type view. If a camera shot has someone centered on the
screen,
from their neck down it has a green cast, the fleshtones from their
neck
Click to expand...
up
are not too bad, and near the top of the screen it will also take on a
greenish cast.
This set uses an LA7672 Jungle IC, and the Picture Tube is # A63AGD01X
At times the picture looks perfect, although every few seconds, you
can
actually see the Tint change, like some type of Correction Circuit
kicking
in. I've seen this on a few other Zeniths, and it's a very annoying
phenomena.
So, using an NTSC Pattern Generator, Purity, and Convergence looks
A-OK,
Click to expand...
but
when actually receiving a broadcast signal, the problems present
themselves.
The B&W Tracking is good, as is Vertical Size, and Horizontal Width.
I know my that my explanation of the problem is sketchy at best.

Any Ideas appreciated ??

Thanks,
Randy J. Evans
Click to expand...
 
Just guesses mind you, but on the VR725, perhaps bad capacitor(s) in a video
preamp or video process module, especially if it's a Panasonic built model,

on the VR-721 perhaps an alignment issue (tape guides, NOT the audio/control
head).


Mark Z.


"Ken_B" <ken5229"at"softhome.net> wrote in message
news:vlqc6ngica7j66@corp.supernews.com...
I have two different problems with two different RCA SVHS VCRs maybe the
brilliant folks of the newsgroup could help with....

Firstly, I have a VR725HF which just developed a color problem. On SLP
playback, it has very weak color which flickers on and off. It's OK at SP
speed. Tapes from another machine show the same symptoms, while tapes from
this machine look normal on another machine. So the problem would be in
playback, not record.

The second VCR, a VR721HF, has distorted sound when a tape recorded on
another VCR or is played. A tape recorded on this machine has distorted
sound when played on the other VCR. But tapes recorded and played back on
this machine sound fine.

Any ideas?

Thanks.

Ken
Click to expand...
 
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